U.S. patent number 7,686,457 [Application Number 11/531,068] was granted by the patent office on 2010-03-30 for projection image display apparatus and multi-projection system.
This patent grant is currently assigned to Canon Kabushiki Kaisha. Invention is credited to Shuichi Kobayashi, Daisuke Ogawa.
United States Patent |
7,686,457 |
Kobayashi , et al. |
March 30, 2010 |
**Please see images for:
( Certificate of Correction ) ** |
Projection image display apparatus and multi-projection system
Abstract
A projection image display apparatus is disclosed which enable
users to observe an image in an overlap area well. The apparatus
comprises a first projector which projects a first image onto a
projection surface, a projection area detector which acquires a
projection area onto which a second projector projects a second
image in a certain area of the projection surface. Further, the
apparatus comprises a projection area controller which controls a
projection area onto which the firs projector projects the first
image, based on an input signal from the projection area
detector.
Inventors: |
Kobayashi; Shuichi (Yokohama,
JP), Ogawa; Daisuke (Utsunomiya, JP) |
Assignee: |
Canon Kabushiki Kaisha
(JP)
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Family
ID: |
37854704 |
Appl.
No.: |
11/531,068 |
Filed: |
September 12, 2006 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20070058140 A1 |
Mar 15, 2007 |
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Foreign Application Priority Data
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Sep 13, 2005 [JP] |
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2005-265867 |
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Current U.S.
Class: |
353/94;
353/30 |
Current CPC
Class: |
G03B
37/04 (20130101); G03B 21/26 (20130101); H04N
9/3147 (20130101) |
Current International
Class: |
G03B
21/26 (20060101) |
Field of
Search: |
;353/30,94,85
;348/745,806 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2004-228824 |
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Aug 2004 |
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JP |
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2005-39849 |
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Feb 2005 |
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JP |
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Primary Examiner: Epps; Georgia Y
Assistant Examiner: Brooks; Jerry
Attorney, Agent or Firm: Rossi, Kimms & McDowell LLP
Claims
What is claimed is:
1. A projection image display apparatus comprising: a projector
which projects a first image onto a projection surface; a
projection area detector that detects an overlap area in which at
least a portion of the first image overlaps at least a portion of a
second image provided on the projection surface and a projection
area controller which controls projection of the first image by the
projector, based on an input signal from the projection area
detector; wherein the projection area controller controls the
projector so as not to project the portion of the first image in
the detected overlap area when the portion of the second image is
provided in a detected overlap area.
2. A multi-projection system comprising: first and second
projectors which respectively project corresponding first image and
second images onto a projection surface; a projection area detector
that detects an overlap area in which at least a portion of the
first image will overlap at least a portion of the second image on
the projection surface and a projection area controller which
controls one of the first and second projectors, based on a
detection result by the projection area detector, so as not to
project the portion of an image corresponding thereto in the
detected overlap area, while the portion of an image corresponding
to another of the first and second projectors is projected in a
detected overlap area.
3. The multi-projection system according to claim 2, wherein at
least one of the first and second projectors is movable.
4. A projection image display apparatus comprising: a first
projector which projects a first image onto a projection surface; a
projection area detector which acquires a projection area onto
which a second projector projects a second image in a certain area
of the projection surface; and a projection area controller which
controls a projection area onto which the first projector projects
the first image, based on an input signal from the projection area
detector; wherein the projection area controller controls the
projection area of the first projector so that the first image is
not projected onto an overlap area in which the first image
projected by the first projector and the second image projected by
the second projector are overlapped with each other.
5. The projection image display apparatus according to claim 4,
wherein an area in which the first image projected by the first
projector and the second image projected by the second projector
are overlapped with each other is acquired by the projection area
detector.
6. The projection image display apparatus according to claim 4,
wherein an area onto which the second image is projected by the
second projector is acquired by the projection area detector.
7. The projection image display apparatus according to claim 4,
wherein, when an area that the first image projected by the first
projector and the second image projected by the second projector
are overlapped with each other is referred to as an overlap area,
the projection area controller controls the projection area of the
first projector so that the first image is projected onto only a
part of the overlap area.
8. A multi-projection system comprising: first and second
projectors which respectively project a first image and a second
image on a projection surface; a projection area detector which
acquires at least one of first and second projection areas onto
which the first and second images are respectively projected by the
first and second projectors; and a projection area controller which
controls at least one of the first and second projection areas,
based on a detection result by the projection area detector wherein
the projection area controller controls the first projector so that
the first image is not projected onto an overlap area in which the
first image and the second image projected by the first projector
and the second projector are overlapped with each other.
9. The multi-projection system according to claim 8, wherein at
least one of the first and second projectors is movable.
10. A multi-projection system comprising: first and second
projectors which respectively project a first image and a second
image on a projection surface; a projection area detector which
acquires an overlap area in which the first and second images
respectively projected by the first and second projectors are
overlapped with each other; a projection area controller which
controls at least one of the first and second projection areas,
based on a detection result by the projection area detector; and an
area indicator which indicates one of the first and second
projectors, wherein the projection area controller controls the
first and second projectors so that a projector indicated by the
area indicator projects an image on the overlap area and the
projector not indicated by the area indicator does not project an
image on the overlap area.
Description
BACKGROUND OF THE INVENTION
The present invention relates to projection image display
apparatuses suitable for projection of images onto a projection
surface using a single or plural projectors and multi-projection
systems.
Multi-projection systems (image display system) are conventionally
used, which project plural images onto a projection surface by
combination of plural projectors.
Of the systems, one is known which displays a magnified image by
arranging plural image display areas onto which the plural
projectors project images in a tiled manner (see Japanese Patent
Laid-Open Application No. 2005-39849).
As another image display system, a so-called stack projection
system is known in which plural projectors are combined and plural
image areas of the respective projectors are overlapped with each
other (see Japanese Patent Laid-Open Application No.
2004-228824).
The multi-projection system disclosed in FIG. 1 of Japanese Patent
Laid-Open Application No. 2005-39849 divides input image
information into plural pieces and displays the pieces of
information by the plural projectors that constitute the system.
This system displays a smooth image that is a mostly seamless image
on a screen.
The stack projection system disclosed in FIG. 1 of Japanese Patent
Laid-Open Application No. 2004-228824 overlaps the projection
display areas of the respective projectors with high accuracy. This
system can obtain a bright projection image by causing the
respective projectors to display the same image information.
However, in a case where the respective projectors display images
different from each other in the multi-projection system, the stack
projection system disclosed in Japanese Patent Laid-Open
Application No. 2004-228824 overlaps the different images. This
results in making it hard to recognize the projection image.
The multi-projection system disclosed in Japanese Patent Laid-Open
Application No. 2005-39849 can display the respective images
independently since the respective projection areas are different
from each other. However, since the projection areas are fixed,
their positions cannot be moved freely.
Further, when a single projector projects an image onto the
projection surface, the image and another image projected by
another projector may overlap with each other.
Furthermore, when the plural projectors project plural images onto
the screen, the projection areas of the images may overlap with
each other thereon.
BRIEF SUMMARY OF THE INVENTION
One object of the present invention is to provide a projection
image display apparatus and a multi-projection system which enable
users to observe an image in an overlap area well in the
above-described cases.
According to one aspect, the present invention provides a
projection image display apparatus comprising a first projector
which projects an image onto a projection surface, a projection
area detector which acquires a projection area onto which a second
projector projects an image in a certain area of the projection
surface, and a projection area controller which controls a
projection area onto which the firs projector projects the image,
based on an input signal from the projection area detector.
According to another aspect, the present invention provides a
multi-projection system comprising first and second projectors
which project images on a projection surface, a projection area
detector which acquires at least one of first and second projection
areas onto which the images are respectively projected by the first
and second projectors, and a projection area controller which
controls at least one of the first and second projection areas,
based on the detection result by the projection area detector.
Other objects and further features of the present invention will
become readily apparent from the following description of the
preferred embodiments with reference to accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an outline view showing the configuration of the
multi-projection system that is Embodiment 1 of the present
invention.
FIGS. 2A, 2B, 3A and 3B are schematic views of projection images in
FIG. 1.
FIG. 4 is a flowchart showing the sequence in Embodiment 1.
FIG. 5 is an outline view showing the configuration of the
multi-projection system that is Embodiment 2 of the present
invention.
FIGS. 6A and 6B are schematic views of projection images in FIG.
5.
FIG. 7 is a flowchart showing the sequence in Embodiment 2.
FIGS. 8A and 8B are schematic views of projection images in
Embodiment 2.
FIG. 9 is an explanatory figure showing another detection area of
the projection area.
FIG. 10 is an outline view showing the configuration of the
multi-projection system that is Embodiment 3 of the present
invention.
FIGS. 11A and 11B are schematic views of projection images in
Embodiment 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A description will now be given of the preferred embodiments of the
present invention by referring to the accompanying drawings.
Embodiment 1
FIG. 1 is an outline view showing the configuration of the main
part of the multi-projection system that is Embodiment 1 of the
present invention.
A first projector 1 and a second projector 2 respectively project
images (video images) onto projection areas 6 and 7 of a screen
(projection surface) 5. Video input signals 9 and 10 are signals
based on images to be displayed by the projectors 1 and 2.
The projection areas 6 and 7 corresponding to the projectors 1 and
2 form an overlap area 8. Therefore, when the projectors 1 and 2
project the images based on the video input signals 9 and 10 onto
the screen 5, the images overlap with each other in the overlap
area 8, resulting in making it hard to recognize the images.
The video input signals 9 and 10 are input to a projection area
controller 4 and converted into video input signals 11 and 12 whose
projection areas are controlled by the controller 4. The video
input signals 11 and 12 are input to the projectors 1 and 2.
The projection area controller 4 is connected to a projection area
detector 3 through a signal line 13. The projection area detector 3
detects the dimensions, shape and the like of the projection areas
6 and 7 projected by the projectors 1 and 2 in a detection area 14
on the screen 5.
The projection area controller 4 restricts the projection areas 6
and 7 formed by the projectors 1 and 2 based on the detection
result of the projection areas 6 and 7 detected by the projection
area detector 3. Specifically, the projection area controller 4
generates from the video input signals 9 and 10 the area-controlled
video input signals 11 and 12, and controls the projection areas 6
and 7 of the projectors 1 and 2 based on these video input signals
11 and 12.
For instance, the projection area controller 4 deletes the
projection area of one of the projectors 1 and 2 in the overlap
area 8.
The embodiment has at least the first and second projectors 1 and 2
which project video images onto the screen (projection surface)
5.
An image display area in the projection area of one of the first
and second projection areas 6 and 7 respectively formed by the
first and second projectors 1 and 2 in the projection surface 5 is
detected by the projection area detector 3. In addition, at least
one of the image display areas formed in the first and second
projection areas 6 and 7 is controlled by the projection area
controller 4 based on the detection result by the projection area
detector 3.
For instance, the projected image by the first projector 1 in the
overlap area 8 is deleted.
In this embodiment, the projection area detector 3 especially
detects the projected image in the area 8 in which the first
projection area 6 formed by the first projector 1 overlaps with the
second projection area 7 formed by the second projector 2 to input
the detection result to the projection area controller 4. The
projection area controller 4 controls the first projection area 6
of the first projector 1 based on the signal (detection result)
input from the projection area detector 3. For instance, the
projection area controller 4 deletes the projection image.
The specific method for detecting the projection areas 6 and 7 and
controlling thereof will hereinafter be described. FIGS. 2A and 2B
schematically show the relationship between the detection area 14
and the projection areas 6 and 7 on the screen 5.
The projection areas 6 and 7 form the overlap area 8. First, as
shown in FIG. 2A, the first and second projectors 1 and 2
respectively display a fully white image 6a and a fully black image
7b on the screen 5 based on the signals from the projection area
controller 4 (not shown in FIG. 2A).
In this state, the projection area detector 3 detects the
projection areas. The projection area detector 3 has a function to
pick up a two-dimensional image, picking up an image that shows a
display state on the detection area 14.
It is possible to recognize the projection area 6a of the first
projector 1 based on the resulting picked-up image.
Next, as shown in FIG. 2B, the second and first projectors 2 and 1
respectively display a fully white image 7a and a fully black image
6b on the screen 5 based on the signals from the projection area
controller 4.
In this state, the projection area detector 3 detects the
projection areas. It is possible to recognize the projection area
7a of the second projector 2 in the detection area 14 based on the
resulting picked-up image.
Thereby, information on dimensions, position, shape and the like of
each of the projection areas 6a and 7a are acquired.
FIGS. 3A and B are explanatory figures showing the control of the
projection areas 6 and 7, schematically showing each area on the
screen 5 as FIGS. 2A and 2B.
When a system user, not shown, indicates the projection area 7 of
the second projector 2 or the projecting area 6 of the first
projector 1 by using an area indicating means 40 as shown in FIGS.
3A and 3B, an image projected by the projector whose projection
area is indicated in the overlap area 8. The position indicated by
the area indicating means 40 is detected by the projection area
detector 3. Thereby, the image displayed in the overlap area 8 is
controlled.
In addition, the projection area controller 4 inputs the video
input signals 11 and 12 to the projectors 1 and 2, respectively,
the signals 11 and 12 being area-controlled such that black display
is performed in an area corresponding to the overlap area 8 in the
video input signals 9 and 10. Black is not necessarily required in
the present invention. Other colors, for instance, dark blue or
full white may be employed.
Performing the black display in this embodiment substantially means
that image projection (display) is not performed.
Further, although the description was made of the case where the
black display was performed or the image projection was not
performed in the overlap area 8, the present invention is not
limited thereto. For instance, the black display may be performed
or the image projection may be not performed in a part of the
overlap area 8.
As described above, according to this embodiment, it is possible to
prevent the image from being hard to recognize even though
projected images are overlapped with each other and to control
display of the projected image in accordance with a user's
intention.
Although the description was made of a multi-projection system
including two projectors in the above-described embodiment, the
number of the projectors in the present invention is not limited
thereto.
FIG. 4 shows an example of the sequence to control the image
projection area in a case where i (i.gtoreq.2) projectors are
used.
STEP 1 (display detection mode) is a process to confirm the
projection area. This step is carried out at the start of the
system or every predetermined time period.
STEP 2 (confirmation of the projectors) is a process to detect how
many projectors are connected to the system. The i projectors are
detected in this step.
STEP 3 (acquisition of the i-th areas), STEP 4 (display and image
pickup of the i-th area), STEP 5 (analysis and storage of the i-th
area) and STEP 6 (determination of end) are processes to store the
i areas sequentially detected by the projection area detector
3.
STEP 7 (end of the display detection mode) is a process to start
the control by the projection area controller 4, based on the
detection result of each area.
STEP 8 (detection of a user-indicated position) is a process to
detect a position indicated by the area indicating means 40 shown
in FIGS. 3A and 3B.
Although fully white display or fully black display was performed
in the detection of the projection areas 6 and 7 in the
above-described embodiment, the present invention is not limited
thereto.
For instance, a grid chart and a frame maybe employed. In addition,
for instance, a blue frame and a red frame may be respectively and
concurrently displayed by the first and second projectors 1 and 2.
In this case, picking up the color frame image by the projection
area detector 3 makes it possible to acquire information on
dimensions, position, shape and the like of each of the projection
areas 6 and 7 simultaneously.
Furthermore, performing the area detection and control of the
projection areas 6 and 7 during projection makes it possible to
achieve a multi-projection system capable of responding
increment/decrement of the overlap area 8 caused by movement of the
projectors 1 and 2.
Although this embodiment showed the case where the projection area
detector 3 and the projection area controller 4 were separated from
each other, they may be configured integrally. Further, the
projectors 1 and 2 may have functions of the detector 3 and
controller 4.
Embodiment 2
FIG. 5 is an outline view showing the configuration of the
multi-projection system that is Embodiment 2 of the present
invention. In FIG. 5, first and second projectors 15 and 16
respectively project images onto projection areas 20 and 21 on a
screen 19.
Video signals 23 and 24 are input to the projectors 15 and 16,
respectively. A projection area detector 17 detects information on
an image 20 projected in a predetermined detection area 25 on the
screen 19 by the first projector 15.
A projection area controller 18 is built in the main body of the
first projector 15 and inputs a video signal generated by adding
area-control to the video input signal 23 based on the detection
result by the projection area detector 17. The projector 15
displays the image on the screen 19, based on the video signal.
A video input signal is input to the second projector 16 as it is,
in other words, without control of the projection area.
The projection areas 20 and 21 corresponding to the projectors 15
and 16 form an overlap area 22, as shown in FIG. 5. Therefore, when
the projectors 15 and 16 project the images based on the video
input signals 23 and 24 as they are onto the screen 19, the images
in the overlap area 22 become hard to recognize.
The specific method for detecting the projection areas 20 and 21
and controlling thereof will hereinafter be described. FIGS. 6A and
6B schematically show the relationship between the detection area
25 and the projection areas 20 and 21 on the screen 19.
The projection areas 20 and 21 form the overlap area 22. First, as
shown in FIG. 6A, the first projector 15 displays a fully black
image on the screen 19 based on the signals from the projection
area controller 18 (not shown in FIG. 6A).
In this state, the projection area detector 17 detects the
projection area 21 other than that of the first projector 15. The
projection area detector 17 has a function to pick up a
two-dimensional image. This makes it possible to recognize the
projection area 21 of a projector other than the first projector
15, that is, the second projector 16.
Next, the first projector 15 displays a fully white image in the
projection areas 20 and 21 on the screen 19. In this state, the
projection area detector 17 picks up an image of the detection area
25 and then detects the projection area 20 of the first projector
15 from the difference between the picked-up fully black image and
the picked-up fully white image.
Since the image in the projection area is controlled by only the
first projector 15, the projection area controller 18 inputs the
video input signal to the first projector 15, the video input
signal being area-controlled based on the detection result by the
projection area detector 17 such that black display is performed in
the overlap area 22.
As a result, only the image projected by the second projector 16 is
displayed in the overlap area 22 as shown in FIG. 6B.
Although this embodiment describes a case where one projector
capable of controlling the projection area and another projector
are included, the same effect can be obtained in a case where two
or more other projectors are included.
FIG. 7 shows the sequence to control the image projection apparatus
in this embodiment.
STEP 11 (acquisition of a first projection area) is a process to
acquire the projection area 20 of the first projector 15.
STEP 12 (display of a fully black image) is a process to display
the fully black image in the projection area 20.
STEP 13 (acquisition of the image A in the detection area) is a
process to pick up the fully black image A projected by the first
projector 15 in the detection area 25.
STEP 14 (acquisition of the image B in the detection area) is a
process to pick up the fully white image B projected by the first
projector 15 in the detection area 25.
STEP 15 (calculation of the difference between the images A and B)
is a process to calculate the difference between the images A and B
picked up at STEPs 13 and 14.
STEP 16 (detection) is a process to detect the projection area 20
of the first projector 15 based on the above-described difference
and the overlap area 22.
STEP 18 (image analysis and determination) is a process to
determine whether or not the image is projected by the other
projector (that is, the second projector) in the detection area 25.
If yes, the process proceeds to STEP 19. If no, the process
ends.
STEP 19 (set of the overlap area) is a process to set the overlap
area 22.
STEP 20 (black display in the overlap area) is a process to perform
black display in the overlap area 22.
Although the projection area controller 18 in this embodiment
displays the fully white and fully black images, the present
invention is not limited thereto.
FIGS. 8A and 8B schematically show the projection areas 20 and 21
like FIGS. 6A and 6B. The projector 15 displays a predetermined
frame 39 on the screen 19, instead of the fully black display.
The projection area detector 17 searches the position of the
predetermined frame 39 and detects the projection area 20 of the
first projector 15. Analyzing an image which is picked up together
with the image in the projection area 20 of the first projector 15
makes it possible to acquire the projection area 21 of the second
projector 16.
Although the description was made of the case where the detection
area 25 included the projection areas 20 and 21 as shown in FIG. 5,
the present invention is not limited thereto. If the detection area
25 includes at least the projection area 20 of the first projector
15, it is possible to obtain a similar effect.
According to this embodiment, even when the position of the second
projector 16 is moved, performing detection and control of the
projection area makes it possible to display an image that has no
image overlapping and is easy to recognize.
Although this embodiment showed the case where the projection area
detector 17 was separated from the projector 15, it may be built in
the projector 15.
Further, both the projection area detector 17 and the projection
area controller 18 may be separated from the projector 15.
Moreover, in this embodiment, the number of the projector may be
one. In other words, the system may be constituted by, for example,
only the projector 15.
Furthermore, the second projector 16 may be treated as an apparatus
not included in the system, and the projection area controller 18
may control images projected by both the first and second
projectors 15 and 16 when the second projector 16 projects the
image.
In this case, this is not a multi-projection system but a
projection image display apparatus.
Specifically, the projector 15 projects an image onto a projection
surface 19. The projection area detector 17 detects a predetermined
area in the projection surface 19. The projection area controller
18 controls the projection area 20 of the projector 15.
The projection area detector 17 detects the projection area 21 of
the projector 16 in the predetermined area 25, the projector 16
being a projector other than the projector 15. The projection area
controller 18 controls the projection area 20 projected by the
projector 15, based on a signal from the projection area detector
17.
Embodiment 3
FIG. 10 is an outline view showing the configuration of the
multi-projection system that is Embodiment 3 of the present
invention.
In FIG. 10, first and second projectors 26 and 32 respectively
project images onto projection areas 35 and 34 on a screen 36.
The projector 26 is electrically connected to the projection area
detector 27 and the projection area controller 30.
The projector 26 is a projector for a large screen, which projects
a video image based on a video input signal 31 onto the screen
36.
On the other hand, the projector 32 is a small-sized portable
projector which displays a video image based on a video input
signal 33. The projection area 34 of the portable projector 32 is
included in, in other words, completely overlapped with a
projection area 35 of the projector 26.
A projection area detector 27 detects an image (projection area 35)
in a detection area 37 on the screen 36. The projector 26 receives
a video input signal 28 which is area-controlled based on the
detection result by the projection area detector 27 and displays an
image based on the video input signal 28.
Accordingly, the projection area controller 30 controls the
projector 26 so that the image projected in the projection area 35
by the projector 26 does not overlap with the image of the
projection area 34 of the portable projector 32.
The method for this control will hereinafter be 5 described. FIGS.
11A and 11B schematically show the projection areas 35, 34 and the
detection area 37.
First, the projector 26 performs fully black display based on the
video input signal 28 from the projection area controller 30 as
shown in FIG. 11A.
The projection area detector 27 has a function to pick up a
two-dimensional image, picking up the detection area 37 in the
state in which the projector 26 outputs the fully black image
35.
At this point, the image in the projection area 34 of the portable
projector 32 is picked up, thereby being confirmed what image
exists in the detection area 37.
Next, the projection area controller 30 displays markers 38, which
indicate four corners of the projection area 35 projected by the
projector 26. The projection area detector 27 picks up the image in
the detection area 37 in this state. Detecting the markers 38 from
the picked-up image specifies the projection area 35 of the
projector 26, as shown in FIG. 11B.
The projection area controller 30 causes the projector 26 to
display a black image only in a part of the projection area 35 of
the projector 26, the part corresponding to the projection area 34
of the portable projector 32. This prevents the image from being
hard to recognize by image overlapping.
Although the projector connected to the projection area controller
30 displays the fully black image and the markers 38 sequentially
when detecting the projection area of the other projector in the
projection area 35 in this embodiment, the present invention is not
limited thereto. The positions of the markers 38 and the position
of the image projected by the other projector may be simultaneously
acquired by image processing on the image including the markers 38
in the detection area 37. The shape of the markers 38 is not
limited to that shown in the figure.
The detection by the projection area detector 27 and the control by
the projection area controller 30 based on the detection result may
be performed not only at the start of the system but also every
predetermined time period. This makes it possible to prevent
overlap of the projected images even when the position of the
portable projector 34 is arbitrary changed.
Although the video input signals 31 and 28 are input through the
signal lines in this embodiment, the signals may be input through
various means such as wireless communication, and the format of the
signals is arbitrary.
When the projection areas are overlapped with each other, a user of
the system can select whether or not to prevent the image
overlapping by the projection area controller 30 through an
interface, not shown.
As described above, according to each of the embodiments, detecting
the projection area of the projector makes it possible to
facilitate detection of overlap of projected images. In addition,
controlling the video input signal for the overlap area and
inputting it to the projector make it possible to prevent overlap
of images.
Moreover, the projection area detector detects the image projected
by the projector other than one of first and second projectors in a
predetermined area on the screen, and recognizes the image
projected by the other projector in the projection area.
Controlling the projection area of the one projector by the
projection area controller based on the detection result makes it
possible to prevent image overlapping.
In particular, it is possible to respond well to changes of the
overlap area due to movements of the projector.
Further, when one of plural projectors which respectively project
images based on plural video input signals is moved, image
overlapping is generated, thereby making recognition of the images
hard.
In contrast, the multi-projection system including plural
projectors which were described in each of the embodiments can
prevent the image overlapping that makes recognition of the images
hard.
Furthermore, it is possible to achieve an arbitrary image space
which is adaptable to changes of the projection area due to
movements of the projector such as a portable projector.
Moreover, according to the above-described embodiments, it is
possible to obtain a multi-projection system that can display
easily-recognizable images even when the images are projected by
plural projectors whose projection areas overlap with each
other.
In addition, according to the above-described embodiments, it is
possible to obtain a projection image display apparatus that
display a predetermined image well even when an image projected by
a single projector and an image projected by another projector
overlap with each other.
Furthermore, the present invention is not limited to these
preferred embodiments and various variations and modifications may
be made without departing from the scope of the present
invention.
This application claims foreign priority benefits based on Japanese
Patent Application No. 2005-265867, filed on Sep. 13, 2005, which
is hereby incorporated by reference herein in its entirety as if
fully set forth herein.
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